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Title: Sensors


1
Center of Excellence for Explosives Detection,
Mitigation, and Response
Detection
Sensors
Characterization
Mitigation
Human Sample
Collected Sample
Near Sample
Remote Sample
Interior Sample
IMS DMS Dr. Eiceman (NMSU) Dr. Karpas (HU)
Sensory Polymers Dr. Lewis (CalTech) Dr. Major
(URI) Dr. Euler (URI)
Metal Oxides Dr. Gregory (URI)
LIF Raman Dr. Parpar (Soreq) Dr Hernandez (UPRM)
THz Spectra Dr. Koch (TU) Dr. Hofmann (TU)
IR Imaging Dr. Kennedy (URI) Dr. Euler (URI)
2
Distributed Bragg Reflectors
Cross-sectional SEM image of a DBR/MC/DBR
structure. Each Distributed Bragg Reflector (DBR)
contains 10 period porous silicon multilayers
with 36 and 59 porosities. The 210 nm thick MC
(between two DBRs) has 36 porosity.
Experimental reflectivity spectra of a MC tuned
to 610 nm.
3
MC-DBR filled with MEH-PPV exposed to TNT
t 0 s
t 50 s
t 250 s
  • TNT is detected with response times at or below
    100 s, depending upon delivery
  • RDX gives weaker but measurable signal

MEH-PPV coated on a flat Si surface
MEH-PPV
4
Explosives Detection using Silane-Based Polymers
Jaycoda S. Major, Ph.D.
Research Goals (1) Preparation of silane-based
polymers for thin-film incorporation into
sol-gel matrix (hybrids) (2) Use of these
materials for the development of chemical
and biological sensors use fluorescence
lifetime and quenching and AFM as mode of
sensing We focus on the detection of nitro
amino containing explosives TNT, TATB, RDX, etc,
possibly peroxides
5
Polymer Structure and Functional Groups
6
Probes Response May Depend on Environment
7
Polymers Designed to be Multi-Functional Sensors
Pyrene Emission (Excite at 337 nm) Responds to
aromatic nitro and amine, e.g. TNT
Complex (Excite at 500nm) Responds to aliphatic
amines
8
Detection by Fluorescence and Lifetime Quenching
Can extract Stern-Volmer quenching constants and
lifetime changes
9
Multi-Functional Sensing Arrays
Nanoparticle arrays are assembled nanoparticles
functionalized with different probes on the same
substrate - no spectral interference
10
Conductive Polymer Composite Array
FabricationNate LewisCalTech, Chemistry
4) Sensor Feature Extraction
5) Array Fingerprint Response
2) Sensor Response Smelling by Swelling
11
Polymer Composite Array Discrimination
(vapor pressure of DMMP Po 1 mmHg)
Hopkins, R.H. Lewis, N.S. Anal. Chem. 2001
12
Polymer Composite Sensors Properties and 2,4-DNT
Sensing
  • alkanes and 1-alcohols exposed at same P/Po give
    same response
  • Generally LOD of any odorant is P/Po 5 x 10-5
    regardless of odorant vapor pressure

Doleman, J.D Severin, E.J. Lewis, N.S.
Proc. Natl. Acad. Sci. USA. 1998 Briglin, S.M.
Freund, M.S. Sisk, B.C. Lewis, N.S.
Proc. SPIE. 2001
13
Polymer Composite Sensors Proposal
  • Typical 2,4-DNT concentration above landmine
    low parts per trillion - need 102 to 103 increase
    in sensor sensitivity
  • Q How to obtain increased sensitivity?
  • Pre-concentration
  • Results in increased sample processing time
    (minutes)
  • Use to verify landmine identified with anomaly
    detectors
  • New polymer systems
  • Floppy polymers self-arrange in presence of
    complementary molecules, providing enhanced
    volumetric and resistive response

polymer in presence of benzene
polymer in air
benzene (vapor)
14
Polymer Composite Sensors Proposal (Continued)
  • Q How to obtain increased sensitivity?
  • Operation of sensors at higher frequencies
  • Currently dc operation (0.1-1.0 Hz)
  • Operation at higher frequencies reduces sensor
    1/f noise
  • Could increase SNR by 103 using current sensor
    materials

Additional goal characterization of lab and
field performance of recently developed
field-ready detector system
15
Detection of Explosives Using Specific Metal
Oxide Catalysts
Sensors and Surface Technology Partnership
Dr. Otto J. Gregory Distinguished Professor of
Chemical Engineering University of Rhode Island
Kingston, RI 02881
A simple, inexpensive gas detection system using
specific 3D transition metal oxides as catalysts
is being developed to unambiguously detect minute
concentrations of specific gas molecules.expl
osives and explosive precursors
  • PAYOFF for DHS
  • early detection of explosive precursors in
    enclosed areas with nearly immediate detection of
    targeted gas molecules
  • w/o interference effects from background gases
  • initial use in suspected bomb laboratories as
    well as airports, subways, train stations and
    other public areas that may be potential targets
  • PROGRAM DETAILS
  • apply combinatorial material synthesis to create
    new catalyst libraries.
  • using the libraries to identify optimal catalyst
    compounds for target molecules
  • produce sensors and signal conditioning to
    demonstrate technology in field trials

October 9, 2007
16
Typical results and apparatus used for testing
ceramic gas sensors w/ metal oxide catalysts
Sensors and Surface Technology Partnership
10 ETOH in water
Sensor response as a function of ETOH in water
(0.1-20) at temperature
exhaust hood
signal conditioning
data acquisition system
personal computer
MFC 1
MFC 2
microheaters
mixing chamber
N2
N2
ETOH/water solution
17
(No Transcript)
18
Fabrication of thin film microheaters using
photolithography techniques
Sensors and Surface Technology Partnership
Perforated Al2O3 substrate
photo-mask
October 9, 2007
19
Wire-wound (12 um dia. Ni coil) version of
microheater gas sensor with DB9 connector
Sensors and Surface Technology Partnership
quartz plate
Al2O3 plate
October 9, 2007
20
Thermal scan of gas sensor w/ CuO catalyst
exposed to ammonia in the gas phase
Sensors and Surface Technology Partnership
ammonia and urea compounds
thermal scans showing gas sensor response at 0.4
W (2 ammonia in water 0.15 in vapor )
October 9, 2007
21
Detection of Target Molecules Combinatorial
Chemistry Technique for Rapid Screening of Metal
Oxide Catalysts
Sensors and Surface Technology Partnership
  • fabrication of thin film microheaters on ceramic
    plates using photolithography and lift-off
    technique snap individual micro- heaters
  • thermal cycling of microheaters coated with oxide
    catalyst combinatorial libraries
  • generate power curves / catalytic response
  • chemical analysis of most responsive libraries
    using SEM/EDS
  • -additional chemical analysis using ESCA to
    obtain chemical bonding information

October 9, 2007
22
Co-sputtering of metal-oxide combinatorial
libraries
Sensors and Surface Technology Partnership
V target
Cu target
aluminum oxide substrate
co-sputtered Cu-V combinatorial library
catalysts combinations CuO-VO, CuO-FeO, others
October 9, 2007
23
Thin film thermocouples (Cu-Constantan) deposited
on reverse side of ceramic plates with deposited
oxide combinatorial libraries
Sensors and Surface Technology Partnership
backside of ceramic plate
front side of ceramic plate
October 9, 2007
24
Apparatus for IR testing of combinatorial
libraries
IR illuminator (500 w)
fire brick
ceramic plate w/catalysts
IR camera
test gas
waveform monitor
MFC 1
MFC 2
monitor
N2
N2
DVD recorder
ETOH/water solution
25
Combinatorial Catalyst Libraries Interrogated by
IR imaging Technique
Sensors and Surface Technology Partnership
Cu rich catalysts
Cu rich catalysts
V rich catalysts
V rich catalysts
October 9, 2007
26
Rapid Screening Protocols
Infrared Imaging
Thin Film Ceramic heaters
Co-Sputtered Libraries
Co-Sputtered Libraries
combinatorial chemistry
heat treatments
combinatorial chemistry
catalyst response
chemical analysis
field testing
target preparation
laboratory testing
catalyst deposition
October 9, 2007
27
After a long day of ESCA analysis..
Sensors and Surface Technology Partnership
October 9, 2007
28
DMS-IMS2 (tandem differential mobility
spectrometry with dual drift tubes for ion
mobility spectrometry)
Gary A. Eiceman Department of Chemistry and
Biochemistry New Mexico State University Las
Cruces, NM 88003
29
MOBILITY SPECTROMETERS AND SOURCES OF
ERRORS (exclusive of sampling, inlet,
electronics)
REACTION REGION
DRIFT REGION
30
FALSE NEGATIVE RESPONSES
REACTION REGION
explosive
Cl-
---------gt explosive Cl-
BKGD
31
FALSE POSITIVE RESPONSE
DRIFT REGION
drift time (ms)
2
15
32
2-D GAS CHROMATOGRAPHY
3.5
Retention time for column no. 2 (seconds)
0.5
Retention time for column no. 2 (minutes)
10
60
33
TANDEM ANALYSIS IN MOBILITY ANALYZERS
Differential Mobility Spectrometry
IMS
sweep of compensation voltage (1 to 10 s)
digital signal averaging with single shutter (30
spectra/s)
34
MINIATURIZATION OF DRIFT TUBES FOR MOBILITY
SPECTROMETRY
R.A. Miller, G.A. Eiceman, E.G. Nazarov, Sensors
Actuators B. Chem. 2000, 67, 300-306.
35
ION MOTION IN DMS ANALYZER
Ground
Top Electrode
?gt0
t2
Gas Flow from Ion Source
To Detector
?0
?lt0
t1
Bottom Electrode
Add DC Here
Waveform Generator
Ground
36
COMPLETE VIEW OF MOBILITY COEFFICIENTS
vd E K(E/N)
K(E/N) K (1 a(E/N))
K (3e/16N)(2? /?kTeff)1/2(1 ?)/? D(Teff)
37
DMS SCANS FOR HMTD
HMTD(?)H
intensity (a.u.)
HMTDO2-
H2OO2-
compensation voltage (V)
38
T-DESIGN FOR DMS-IMS2
ISIMS, Maffliers, France 2005
39
DMS-IMS2 Breadboard
PHOTOGRAPH OF 2nd VERSION
40
IMS drift time (ms)
0
Toluene
-5
RIP
DMS compensation voltage (V)
-10
-15
-20
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Ko1.86cm2s-1V-1
41
IMS drift time (ms)
2
0
-2
DMS compensation voltage (V)
-4
-6
-8
-10
42
0
-5
-10
DMS compensation votage
-15
-20
-25
-30
1.0
1.5
2.0
2.5
3.0
3.5
4.0
IMS drift time (ms)
43
0
-5
-10
DMS compensation votage
-15
-20
-25
-30
1.0
1.5
2.0
2.5
3.0
3.5
4.0
IMS drift time (ms)
44
Summary
RESEARCH GRADE IMS _at_ NMSU
45
Summary
RESEARCH DMS IMS _at_ NMSU
46
Acknowledgements
CONCLUSIONS ON DMS-IMS2
1. DMS-IMS2 proven in lab and taken to 2nd level
with industry partners
2. Multiple modes of operation high flexibility
3. Advantages demonstrated in separating ions to
avoid false positives
4. NMSU team rescaling for improved resolution
and further innovation on interface between DMS
and IMS
47
IMSIsraeli Approach The
Israeli IMS investigation will take 3 approaches
to improving sensitivity studying the
ionization processes controlling of parameters
in the ionization chamber sample inlet
characteristics. Ionization processes wo
ionization pathways- UV lamp electrical corona
discharge will be examined. Ionization chamber
parameters The will focus on control parameters
such as drift tube temperature, flow rate of
carrier gas, size of ionization chamber,
electric field used for ions acceleration. Sampl
e inlet Focus will be on heating profiles
Zeev Karpas (BGU)
48
A Handheld All-Fiber Terahertz Spectrometer for
the Detection of Liquid Explosives
C. Jansen, M. Koch
?
49
Talk outline
  • Introduction of Our Team
  • Terahertz Time Domain Spectroscopy
  • Our Vision A Reliable, Handheld Liquid
    Explosives and Hazardous Material Detector
  • Conclusion and Outlook

27.06.2018
Terahertz Systems Group
49
50
  • Introduction of Our Team
  • Terahertz Time Domain Spectroscopy
  • Our Vision A Reliable, Handheld Liquid
    Explosives and Hazardous Material Detector
  • Conclusion and Outlook

27.06.2018
Terahertz Systems Group
50
51
Technical University of Braunschweig
  • Braunschweig received the German City of
    Science 2007 award
  • The region of Braunschweig has the highest
    research and development intensity in whole
    Europe with more than 7.1 of the GDP
    attributed to RD activities
  • The Technical University of Braunschweig is
    one of Germanys highest ranked engineering
    institutions
  • A successful exchange program with the
    University of Rhode Island (URI) exists since
    1989 with more than 300 participating
    engineering students so far

Technical University Carolo-Wilhelmina
Braunschweig
27.06.2018
Terahertz Systems Group
51
52
The Terahertz Systems Group Braunschweig
  • The Terahertz Systems Group in Braunschweig is
    the leading instituition for terahertz
    research in Germany
  • It consists of 13 Ph.D. students and is headed
    by Prof. Martin Koch, who is currently the
    president of the German Terahertz Center (DTZ)
    and the co-founder of the Terahertz
    Communications Lab (TCL)

27.06.2018
Terahertz Systems Group
52
53
Core Competence
  • Our expertise includes
  • Terahertz Time Domain Spectroscopy (THz TDS) on
    liquids, plastics and solid explosives
  • System integration of rugged fiber-coupled
    terahertz time domain spectrometers for
    industrial applications
  • Design of quasi-optical terahertz components and
    devices (dielectric Bragg reflectors,
    modulators, aspherical lenses)
  • High-precision data evaluation algorithms suited
    for complex sample geometries

27.06.2018
Terahertz Systems Group
53
54
  • Introduction of Our Team
  • Terahertz Time Domain Spectroscopy
  • Our Vision A Reliable, Handheld Liquid
    Explosives and Hazardous Material Detector
  • Conclusion and Outlook

27.06.2018
Terahertz Systems Group
54
55
The Terahertz Frequency Range
The Terahertz Range
27.06.2018
Terahertz Systems Group
55
56
What kind of information can terahertz
spectroscopy deliver?
Transitions between discreterotational states of
polar molecules
Gas
Absorption
Movement within the network (strongly damped
oscillations)
Absorption
Liquid
Lattice vibrations of the crystal (transversal
optical phonons)
Semi-conductor
Absorption
Collective vibrations of atomicgroups within
molecules
Molecule
Absorption
Frequency
27.06.2018
Terahertz Systems Group
56
57
A conventional free-space Terahertz Time Domain
Spectrometer (THz TDS)
TiSappire
Ar-Ion laser
frequency dependent refractive index
THZ-TDS
frequency dependent absorption coefficient
27.06.2018
Terahertz Systems Group
57
58
Disadvantages of conventional free-space THz TDS
systems
  • Problems of free-space systems
  • free-space systems are very sensitive
  • very bulky, need a lot of space on an optical
    table
  • rather expensive (commercial systems cost
    more than 200.000)

Use an innovative all-fiber approach, which can
provide stable operation as well as reduced size
and costs
27.06.2018
Terahertz Systems Group
58
59
  • Introduction of Our Team
  • Terahertz Time Domain Spectroscopy
  • Our Vision A Reliable, Handheld Liquid
    Explosives and Hazardous Material Detector
  • Conclusion and Outlook

27.06.2018
Terahertz Systems Group
59
60
Handheld liquid explosives detector
Our Vision
Hazardous Material Database
Control Module
Femtosecond Fiber Laser
27.06.2018
Terahertz Systems Group
60
61
0-Reflection-Mode THz TDS Handheld Transceiver
Head
Transceiver with
precollimating optics
Focussing lens
?
Micro delay rail
liquid under test
27.06.2018
Terahertz Systems Group
61
62
Steps of a single scan
THz Reflection Scan
Comparision with material database
Hazardous Substance
Safe Liquid
27.06.2018
Terahertz Systems Group
62
63
  • Introduction of Our Team
  • Terahertz Time Domain Spectroscopy
  • Our Vision A Reliable, Handheld Liquid
    Explosives and Hazardous Material Detector
  • Conclusion and Outlook

27.06.2018
Terahertz Systems Group
63
64
Conclusion
  • All-Fiber Terahertz Time Domain Spectrometer can
    provide reliable liquid explosives detection
  • Short scanning times and high throughput are
    possible
  • The Terahertz Group Braunschweig is capable to
    realize this potential to the fullest extend

27.06.2018
Terahertz Systems Group
64
65
Remote Vapor Enhancement
  • NRC Soreq
  • Electro-Optics Division
  • Dr. Talya Arusi-Parpar

66
Background
  • A unique method was developed to enhance remotely
    vapor concentrations of explosives.
  • Proof of concept was demonstrated with
    conjunction of our explosive remote detection
    system (PLP/LIF) showing a significant
    sensitivity enhancement of about three orders of
    magnitude.
  • Research is required for in-depth understanding
    of the underlying physics and dynamics, in order
    to be able to adapt the method for remote
    detection purposes.

T. Arusi-Parpar et. al., Applied Optics,
Vol.40, 6677-6681, 2001. T. Arusi-Parpar et
al, Stand-off detection of suicide bombers and
mobile subjects, Springer Verlag, NATO Program,
2006.
67
Impact Potential Applications for stand-off
detection
  • Can enhance sensitivities and ranges of all
    existing LIDAR, DIAL systems and all other vapor
    detection methods.
  • Extension of detection Range and sensitivities of
    explosives (e.g. PLP/LIF).
  • By this method explosive detection ranges can be
    increased by a factor of 10-100.

68
Vapor detection inherent limitations for
stand-off detection
  • Most explosives have a very low vapor pressure
  • Low vapor concentrations are difficult to detect.
  • Requires very sensitive, complex systems.
  • Natural evaporation dynamics.
  • Temporal and spatial vapor behavior.
  • Very sensitive to ambient conditions
  • Turbulence, atmospheric conditions.

69
Essence of Proposal
  • Fundamental research
  • Understanding the physics of induced evaporation
    (heating/ablation).
  • Modeling of evaporation process.
  • Explosive plume distribution and dynamics (short
    range).
  • Characterization of evaporation effect on
    different explosives and substrates.

70
Demonstrated effect at Soreq by PLP/LIF
  • Remote detection demonstrated successfully within
    controlled environment.
  • Demonstrated detection of
  • Time response a few seconds.

TNT mixed in Sand (lt1 TNT) SEMTEX C4 Composition B ANFO DNT RDX Crystalline form With Plasticizer PETN Crystalline With Plasticizer
71
Enhanced Results (under well controlled
conditions)
72
Suggested Program Plan
  • Year 1 Literature survey, setup of laboratory
    and development of experimental tools
  • Year 2 Study of evaporation mechanisms (ablation
    versus heating), Study of interaction depth.
    Modeling of evaporation process in terms of
    explosive residue mass loss.
  • Year 3 Characterization of vapor enhancement of
    different explosives, various substrates
    (handles, plastic, leather etc.). Study of the
    effect of different irradiation regimes.
    (wavelength, pulse length, intensities, rep
    rates).
  • Year 4 Mapping of plume distribution and
    dynamics.

73
Raman Telescope For Remote Spectroscopic
Detection of Explosives and Other Threat Agents
Principal Investigator Professor Samuel P.
Hernandez-Rivera, Ph.D. Department of Chemistry,
UPRM
University of Rhode Island (URI) and its partners
to establish a Department of Homeland Security
(DHS) Center of Excellence (COE) Explosive
Detection, Mitigation and Response.
74
OVERALL GOALS
  • Predict performance of UV-Raman sensors as a
    function of excitation wavelength.
  • Investigate if operating in this new spectral
    window introduce new problems? For example, does
    shifting the excitation from 248 nm to 266 nm
    introduce overwhelming interference from
    laser-induced breakdown of interrogated surfaces
    and/or fluorescence from the environment or the
    agents themselves?
  • Design, build and test UV, VIS and NIR systems.

75
Project Description
  • Transitioning the chemical sensing capabilities
    of the Raman Telescope technology to remote
    sensing of explosives.
  • Define limits of detection for 266 nm excitation
    relevant to explosives detection (e.g., physical
    constants for explosives, target thickness,
    target concentration, etc)
  • Refine an existing model to support hardware
    optimization for remote sensing of explosives
  • Identify laser parameters that minimize
    interference from LIBS signals generated while
    interrogating common surfaces. These parameters
    include pulse width, pulse energy, beam profile
    at focal plane (energy/area), number of LIB
    signals in the Raman-shift window, and the
    dependence of these parameters on excitation
    wavelength

76
RAMAN SIGNAL STRENGTHS FOR EXPLOSIVES
-


-

-
N
N

-
Nitroaromatic TNT (shown) and DNT
Mixed Nitroaromatic/Nitramine Tetryl
Nitramines RDX (shown) and HMX
  • Raman-scattering absorption cross sections of
    the nitroaromatic nitramine groups dictate
    which excitation wavelengths yield the strongest
    Raman return signals
  • 1) Wavelength Dependence of Raman Scattering
  • - n4 effect 266 nm light scatters 17x more
    strongly than 532-nm light
  • - resonance enhancement absorption of UV
    light can increase signal by 10-103
  • 2) Absorption Effects
  • - Absorption limits laser penetration into the
    sample and reduces transmission at the
    Raman-band wavelength
  • - Interaction Depth is the sample thickness
    that yields 90 of the return signal
  • expected from an infinitely thick sample at a
    given laser power.

77
BULK DETECTIONTNT, RDX AND C4
Bulk solid sample of RDX
Bulk solid sample of C4
Bulk solid sample of TNT
  • 262-nm excitation affords good SNR from bulk
    samples
  • Return strengths from bulk targets are larger
    when the excitation wavelength is not absorbed by
    the target
  • The relative signal strengths in these plots do
    not reflect performance for trace concentration
    levels

78
OPTIMIZATION OF DESIGN
Collection capability of signal and alignment
should be well known in order to be able to
predict and infer the detection limits and to
project the improvement to new designs!!!
79
Human Factors Unconventional Approaches to
Identifying Malicious Intent
  • IR imaging detection of people
  • Humans emit IR radiation centered at about 10 mm
  • Physiological responses can change the local
    temperature, which can be observed using IR
    imaging
  • IR radiation can be blocked by concealed items
    (e.g., weapons, explosives)
  • IR imaging is noninvasive and can be done
    remotely

80
Human Factors Unconventional Approaches to
Identifying Malicious Intent
Light streak higher temperature, associated
with inflammation and lower back pain
Dark spot lower temperature, associated with
the sinus blockage
81
Human Factors Unconventional Approaches to
Identifying Malicious Intent
  • Approaches for Explosives detection
  • Weapons, IEDs will block IR emission, giving
    dark images
  • Physiological responses can emotional intent
    be identified?
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